kernel/address_arbiter: Convert the address arbiter into a class

Places all of the functions for address arbiter operation into a class.
This will be necessary for future deglobalizing efforts related to both
the memory and system itself.

src/core/hle/kernel/kernel.h

@@ -18,6 +18,7 @@ struct EventType;
 
 namespace Kernel {
 
+class AddressArbiter;
 class ClientPort;
 class HandleTable;
 class Process;
@@ -67,6 +68,12 @@ public:
     /// Retrieves a const pointer to the current process.
     const Process* CurrentProcess() const;
 
+    /// Provides a reference to the kernel's address arbiter.
+    Kernel::AddressArbiter& AddressArbiter();
+
+    /// Provides a const reference to the kernel's address arbiter.
+    const Kernel::AddressArbiter& AddressArbiter() const;
+
     /// Adds a port to the named port table
     void AddNamedPort(std::string name, SharedPtr<ClientPort> port);